Electromechanical watch



June 17, '1969 WALDQURGER ET AL 3,449,904

ELECTROMECHANI CAL WATCH Filed on. 27, 1966 Sheet of s 23 FIG.1

III

June 17, 1969 DB'URGER ETAL 3,449,904

ELECTROMECHANICAL WATCH Filed oct. 27, 1966 I I Sheet 2 of s June 17, 1969 WALDBURGER ETAL 3,449,904

ELECTROMECHANICAL WATCH Sheet Filed Oct. 27, 1966 FIGS FIG]

United States Patent US. Cl. 58-23 9 Claims ABSTRACT OF THE DISCLOSURE This disclosure relates to an electromechanical watch having a mechanical resonator serving as a time base and a driving member and consisting of two frames symmetrically secured to a common central part disposed between the frames, with magnets secured on the outer side of the frames, the common central part being perforated and connected to a foot by a diminished section in such a way as to ensure dynamic coupling of the two frames, with driving coils in a circuit cooperating with the magnet for maintaining the flexural oscillation of the frames and a hand setting mechanism for the watch positioned between the frames.

Resonators of this type oscillate at a relatively low frequency and are free of error due to the differences in the frequency of oscillations occurring when the resonators are in different positions. Nevertheless, their practical use in a wrist watch has not heretofore been possible. The particular arrangement of such a resonator presents new problems with respect to the placement of the various components of the watch such as the hands setting mechanism, the hands and the energy source.

The present invention precisely has for object to solve these problems.

The electromechanical watch according to the invention is characterised by the fact that such frames are rectangular and comprise a central common perforated part secured to the foot by a diminished section in such a way as to ensure the dynamic coupling of the two frames, and that the hands setting mechanism is positioned between the frames.

The accompanying drawing represents by way of example one embodiment of the object of the invention.

FIGURE 1 shows in a plan view the essential components of a wrist watch.

FIGURE 2 shows a cross sectional view thereof.

FIGURE 3 shows the hand setting mechanism.

FIGURE 4 shows a detail of FIGURE 3.

FIGURE 5 shows the hand mechanism in its hand setting positions.

FIGURES 6 and 7 show details of FIGURE 5.

The watch shown on FIGURES l and 2 comprises a circular plate on which is mounted a resonator 2 having the shape of a figure eight with flattened loops 3, 4 to form rectangular frames symmetrically arranged with respect to a diameter 5 of the watch and linked in the centre of the latter by a perforated part 6, itself connected to foot 7 by a diminished section 8 in such a way as to ensure the dynamic coupling of the two frames.

Each of the outer sides 3a, respectively 40, of the frames carry magnets 9, respectively 10, forming simultaneously the oscillating masses. These magnets consist of U-shaped elements the wings of which carry on their inner surfaces permanent magnets 11 and 12, 13 and 14 respectively, cooperating with their pick up coils 15 and driving coils 16 on the one hand with driving coil 17 on the other hand. The oscillating masses oscillate in the plane of the frames in counter phase in the direction of arrow 18 under the ice influence of currents circulating in the coils and form a system dynamically balanced and with a period of oscillation practically independent of the orientation of the of the system in space.

The resilient energy is distributed in the frames in such a way as to avoid high mechanical tension. The oscillation is maintained in a known manner by means of a transistorized amplifying circuit, not shown, linking the pick up coil to the driving coils and to the energy source.

These coils of very small thickness are mounted on insulators 19, respectively 20, extended beyond the outer edges of the coils in order to be secured on plate 1 of the watch by means of screws 21, 22, 23 and 24. These coils have their rectilinear portions 150, 16a and 17a: positioned between the polar pieces of each of the transducers, while their outer parts 15b, 16b and 17b run along the periphery of the watch and bear on the insulators 19 and 20.

The use of very flat coils in the arrangements of the transducers in a central partof the watch save considerable space along the periphery of the watch, which permits either a chamfering of the periphery of the case or the lodging of a date crown 25 such as shown on FIGURE 2. w

The maintenance energy source consists of a cylindrical elongated cell 26 mounted parallel to frame 3 and partially engaged therein.

The diameter of this cell is small enough so as not to increase the total thickness of the case which is determined principally by the transducers.

The transformation of the oscillating movement into rotational movement is elfected by means of a pawl 31 secured to the outer bar 4a of frame 4.

This pawl drives a ratchet wheel 32 forming the first mobile of the movement. The rotation in the opposite direction of this ratchet wheel is prevented by the stop pawl 60 secured on plate 1.

The gear train schematically represented on FIGURE 1 and which will be described in detail with respect to FIGURE 3, leads to the second pinion at the centre 42 and at the centre wheel 43, then drives the usual minute train comprising a snap-on cannon pinion and the cannon wheel. The cannon pinion, the cannon wheel, and the seconds shaft in the centre pass through the circular opening 6 provided in the resonator.

Between the frames of the resonator is provided a space for placing the hands setting mechanism. This mechanism is shown in detail on FIGURES 3 to 7. During setting, the resonator is disengage from the ratchet wheel and simultaneously the movement is braked.

In FIGURE 3, there will be recognized a driving pawl 31 cooperating with the ratchet wheel 32, as well as the stop pawl 60 mounted as close as possible to the driving pawl in such a way that their relative operating phases can be adjusted one to the other in precise manner.

The rotational movement of the ratchet wheel 32 is then transmitted by means of pinions 33, 34, 35, 36 and 37 and wheels 38, 39, 40 and 41 operating the frequency division necessary to the seconds pinion 42 in the centre of the movement, the seconds pinion bearing the centre seconds hand 45, and to the centre Wheel 43 frictionally mounted on the centre shaft stalf. The movement is transmitted to minutes hand 46 and to the hours hand 47 by means of a gear train of the usual type comprising intermediate wheel 44 and a snap-on cannon pinion.

The device for disconnecting the resonator comprises a lever 48 engaging by a stud 51 in an annular groove of the setting stem 50. This bolt is maintained in position by a spring 49.

The setting pinion 52 is secured on the setting stem 50 by a key 53. The braking device consists of a lever 54 pivoted at 54a and maintained against the extremity 56 of the setting stem 50 by means of spring 55.

The working bent extremity of lever 48 bears an eccentric 68 shown in detail on FIGURE 4. This eccentric is provided with an annular groove 69 and by a screw plug 70 permitting adjustment of the position of the eccentric with respect to its mounting point in the lever 48. In the connected position shown in FIGURES 3 and 4, the driving pawl 31 moves freely in groove 69, the horizontal faces of which limit the vertical movements of pawl 31, which in case of shock might leave the teeth of the click wheel 32. However, the main purpose of the eccentric is to disconnect pawls 31 and 60 from the ratchet wheel. The position for disconnecting the pawl and for setting the hand is shown in FIGURES 5, 6 and 7. By pulling on the setting stem 50 (FIGURE there are performed three operations, which are, however, effected by independent members, and, accordingly, readily variable. On the one hand, the lever 48 passes from the normal working position to the hands setting position. During this movement, eccentric 68 disengages first the driving pawl 31 from the teeth of the ratchet wheel 32, pawl 31 (FIG URE 6) coming to bear then against the stop pawl 60 freeing it from the ratchet wheel. Additionally, the extremity 63 of the braking lever 54 first follows the withdrawal movement of the setting stem 50 under the influence of spring 55 until the extremity 62 of the brake comes to bear on the teeth 66 of the middle wheel 41 to brake it. The setting stem 50 departs then from lever 54, leaving the pull of spring 55 to keep the lever in engagement with wheel 41. Furthermore, the setting pinion 52 comes to mesh with the small setting wheel 59. In this position by means of the large setting wheel 58 and the wheel 57, it is then possible to drive the minute hand 46 and the hour hand 47.

These three movements must be perfectly coordinated.

In the hands setting position the resonator continues to function wihout driving the ratchet wheel 32.

Owing to the fact that the two pawls are disengaged by a single eccentric 68 (FIGURE 6) the driving panel 31 comes to bear and rub against the stop pawl 60. The pawls being very close one to the other, there is danger that the end 67 of driving pawl 31 may rub between the ruby palette 71 of pawl 60 and the elbow 65 of the hook of the pawl 60 in which is secured the ruby palette. In order to remedy this state of affairs, there is selected a ruby 71 slightly longer than that of the driving pawl 31.

FIGURE 7 shows how lever 54 comes to bear against the teeth of the middle wheel 41. Extremity 62 of this lever has a concave surface 64 the radius of curvature of which is equal to the outer radius of the middle wheel 41. There is thus guaranteed an instantaneous blocking of the middle wheel 41 when the setting stem is pulled.

What is claimed is:

1. In an electromechanical watch, a mechanical resonator serving as a time base and a driving member and consisting of two frames symmetrically secured to common central pin disposed between the frames, with magnets secured on the outer sides of said frames, said frames having a perforated central common part connected to said pin by a diminished section in such a way as to ensure the dynamic coupling of said two frames; driving coils in a maintenance circuit cooperating with said magnets for maintaining the fiexural transversal oscillation of said frames and a hand-setting mechanism for said watch positioned between said frames.

2. Watch according to claim 1, wherein said magnets consist of U-shaped members having wings bearing on their inner faces permanent magnets mounted above and below that part of each of said driving coils which is directed towards the centre of the watch, the width of said coils being several times greater than the thickness thereof.

3. Watch according to claim 1, wherein the outer part of said coils follows the edge of the plate of the watch.

4. Watch according to claim 1, wherein at least one of said frames, has an opening and at least one battery is disposed therein at least partially, said battery feeding said maintenance circuit for said watch.

5. Watch according to claim 1, having a gear train wherein said hand setting mechanism comprises means for simultaneously disconnecting said resonator from the gear train and for braking the wheel works.

6. Watch according to claim 5, having a driving pawl secured on said resonator and a stop pawl, said two pawls being mounted in close proximity to one another and cooperating with a click wheel, said hand setting mechanism comprising two levers simultaneously operated by the setting stem of said watch.

7. Watch according to claim 6, wherein one of said levers comprises a disconnecting lever bearing at one extremity thereof an adjustable eccentric stud having a groove, wherein said driving pawl moves freely during normal operation of said watch and comes to bear, when disconnected from said ratchet wheel against the bottom of said groove, thereby bending the driving pawl, said lever ensuring, at the same time, limitation of the driving pawls movement perpendicular to its oscillation plane in case of shock.

8. Watch according to claim 7, wherein the stop pawl is positioned so as to be disengaged from the ratchet wheel by the driving pawl during disconnection.

9. Watch according to claim 6,' wherein one of said levers comprises a braking lever having a concave surface at one end thereof, the radius of curvature of the said surface corresponding to the radius of the wheel to be braked.

References Cited UNITED STATES PATENTS 3,150,337 9/1964 Allison. 3,262,259 7/1966 Bennett et a1 58-8l.5

RICHARD B. WILKINSON, Primary Examiner.

E. C. SIMMONS, Assistant Examiner.

U.S. Cl. X.R. 

